“Analysis of Coal Quality on Mining Front and Ship Loading in East Kalimantan Province: Evaluasi Kualitas Batubara Pada Front Penambangan Dan Ship Loading Di Provinsi Kalimantan Timur”. JURNAL GEOCELEBES, vol. 6, no. 1, Apr. 2022, pp. 87-92, https://doi.org/10.20956/geocelebes.v6i1.19729.